The embodiments herein generally relate to systems and methods of optical computing and, more specifically, to optical computing devices comprising broadband angle-selective filters.
Optical computing devices, also commonly referred to as opticoanalytical devices, may provide improved sensitivity and detection limits when integrated computational elements are used. Such integrated computational elements may provide a relatively low cost, rugged, and accurate system for monitoring petroleum quality for the purpose of optimizing decision making at a well site and efficient management of hydrocarbon production. In some applications, the integrated computational elements may be useful in improving detection limits when determining a particular characteristic of a sample, such as a substance, compound, or material present in a wellbore, or other technology fields including, but not limited to, the food and drug industry, industrial applications, mining industries, or any field where it may be advantageous to determine in real-time a characteristic of a substance, compound, or material.
Stray light reflections in optical computing devices, however, may interfere with the measurement of the sample when the reflections are not from the sample itself but from some other source. Such stray light reflections may be a significant fraction of the total light (e.g., electromagnetic radiation) detected in the optical computing device. If not effectively reduced or otherwise prevented, the stray light may vary the resulting sample signal, resulting in substantially reduced accuracy, precision, sensitivity, and limit of detection. For example, such variations include, but are not limited to, large bias voltages observed in a detector, lower resolution in spatial images, detector saturation effects, combinations thereof, or the like. Traditionally, such stray light reflections are controlled or minimized using imaging lenses, anti-reflective coatings, physical apertures, and the like. However, such techniques may not adequately remove stray light reflections, resulting in improved, but still non-optimal signals related to the sample of interest